1. Technical Field
The invention is generally related to the field of lighting and more particularly to an improved solid state lamp which according to one aspect is adapted to be installed in a standard incandescent or fluorescent lamp socket, such as an Edison or GU-24 socket, for example.
2. Background of the Related Art
One of the largest categories of incandescent lamps in use today is the “A” lamp or Edison lamp widely employed in the United States. FIG. 1 shows an example of an A lamp incandescent bulb 100, a Philips 75 watt (W) 120 volt (V) A 19 medium screw (E26) base frosted incandescent, having part number PL234153. Bulb 100 has a screw base 102 for screwing into a 120V lighting fixture and sealed glass bulb 104. Bulb 100 also has a nominal height, h, of 4.1 inches and a nominal width, w, of 2.4 inches. The upper portion of bulb 100 is a hemisphere and the lower portion necks down to the screw base 100. In Europe and elsewhere other standard incandescent bulb mounting arrangements are employed. All such incandescent lamps are among the least energy efficient designs in use. The exemplary Philips bulb provides 1100 lumens using 75 watts of energy or 14.67 lumens/watt. As a result, many jurisdictions are mandating the phase out of such bulbs, and many consumers are beginning to phase out their use on their own.
Compact fluorescent lamps have been developed as retrofit replacements for the standard incandescent socket. While more efficient, these fluorescent lamps present their own issues, such as environmental concerns related to the mercury employed therein, and in some cases questions of reliability and lifetime.
FIG. 2 shows an example of a compact fluorescent bulb 200 employing a GU-24 lamp base 202. GU describes the pin shape and 24 the spacing of the pins which is 24 mm. Pins 204 and 206 in base 202 are inserted into a socket such as socket 210 of FIG. 2 and then twisted to lock bulb 200 in place. Power is connected to base 210 by electrical wiring 214.
A number of light emitting diode (LED) based A lamp replacement products have been introduced to the market. FIG. 3 illustrates an exploded view of a Topco Technologies Corp. LED lamp 300 having a lamp housing 310 comprising screw in plug 302, first cap 304, second cap 306, and lampshade 308. Lamp 300 also includes LED light source 320, heat sink 330, and control circuit 340. In another embodiment, a cooling fan is employed. Further details of lamp 300 are found in U.S. Patent Application Publication No. 2009/0046473A1 which is incorporated by reference herein in its entirety. Such products typically utilize some sort of upper hemisphere shaped body for emitting light at the top of the lamp. A lower or bottom portion of the lamp, the portion which transitions to the neck and screw base, is utilized for they mal management and to enclose the power supply.